SummaryBackground: Abnormal morphology of the anterior inferior iliac spine (AIIS) and the subspine region of the acetabular rim are increasingly being recognised as a source of symptomatic extra-articular hip impingement. This review article aims to highlight important differences in the pathogenesis, clinical presentation and management of extra-articular hip impingement from both the AI-IS and subspine bony regions, and the outcome following surgical intervention. Methods: A literature review was undertaken to examine the supporting evidence for AIIS and subspine hip impingement. A narrative account of the Author's professional experience in this area, including operative technique for arthroscopic correction, is also presented. Results: Abnormal morphology of the AIIS and subspine region has been classified using cadaveric, radiological and arthroscopic means; the clinical presentation and operative treatment has been documented in several case series studies. Dual pathology is often present -recognition and treatment of both intra-and extra-articular components are necessary for good postoperative outcome. Conclusions: AIIS and sub-spine hip impingement should be considered as distinct pathological entities, which may also co-exist. Symptom relief can be expected following arthroscopic deformity correction with the treatment of concomitant intra-articular pathology. Failure to recognise and treat the extra-articular component may affect postoperative outcome. Level of evidence: V.

No abstract

Aim: To examine the pathogenesis and clinical presentation of sports-related femoroacetabular impingement (SRFAI) in a large consecutive series of symptomatic athletes. Methods: Between January 2009 and February 2017 prospectively collected data from competitive athletes within the Gaelic Athletic Association (GAA), and who subsequently underwent arthroscopic treatment for symptomatic FAI, were analysed. Data was collected using internationally validated health questionnaires (Harris Hip Score, UCLA, SF-36, WOMAC) and recognised clinical (ROM, symptom presentation, provocation tests) and radiological (AP pelvis, Dunn, False profile) indicators/measures of FAI. Results: A total of 1021 consecutive cases (mean 26.6 ± 6.2 years) were included. In every case, conservative treatment failed to resolve symptoms with athletes attending an average of 2.4 ± 1.1 health care professionals prior to referral. Symptoms developed gradually (78%) and consisted primarily of groin pain (76.1%) and hip stiffness (76.5%) following activity. An acetabular rim deformity (pincer) was present in all cases; a cam deformity in 72.1%. The prevalence and degree of cam deformity increased with progressing age groups ( p < 0.001); mean lateral centre-edge angle remained static ( p = 0.456). Increasing CEA, alpha angle and presence of rim fracture was associated with a reduction in all ranges of hip movement ( p < 0.001). Conclusion: Symptomatic SRFAI presented in this large series of GAA athletes failed to resolve with non-operative treatment. Increasing hip deformity resulted in poorer ROM. Abnormal acetabular morphology remains static with increasing athletic age while cam deformity is progressive and most likely a secondary pathology.

Background: Measures of clinically meaningful improvement in patient-reported outcomes within orthopaedics are becoming a minimum requirement to establish the success of an intervention. Purpose: To (1) define the minimal clinically important difference (MCID) at 2 years postoperatively in competitive athletes undergoing hip arthroscopic surgery for symptomatic, sports-related femoroacetabular impingement utilizing existing anchor- and distribution-based methods and (2) derive a measure of the MCID using the percentage of possible improvement (POPI) method and compare against existing techniques. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: There were 2 objective outcome measures—the modified Harris Hip Score (mHHS) and 36-Item Short Form Health Survey (SF-36)—administered at baseline and 2 years postoperatively. External anchor questions were used to determine the MCID through mean change, mean difference, and receiver operating characteristic (ROC) techniques. Distribution-based calculations consisted of 0.5 SD, effect size, and standard error of measurement techniques. The POPI was calculated alongside each technique as an achieved percentage change of maximum available improvement for each athlete relative to the individual baseline score. The impact of the preoperative baseline score on the MCID was assessed by assigning athletes to groups determined by baseline percentiles. Statistical analysis was performed, with P < .05 considered significant. Results: There were 576 athletes (96% male; mean age, 25.9 ± 5.7 years). The MCID score change (and POPI) for the mHHS and SF-36 ranged from 2.4 to 16.7 (21.6%-63.6%) and from 3.3 to 24.9 (22.1%-57.4%), respectively. The preoperative threshold value for achieving the ROC-determined MCID was 80.5 and 86.5 for the mHHS and 70.1 and 72.4 for the SF-36 for the patient-reported outcome measure (PROM) score– and POPI-calculated MCID, respectively. Through the commonly used mean change method, 40.0% (mHHS) and 42.4% (SF-36) of athletes were unable to achieve the MCID because of high baseline scores and PROM ceiling effects compared with 0% when the POPI technique was used. A highly significant difference for the overall MCID was observed between preoperative baseline percentile groups for the mHHS ( P = .014) and SF-36 ( P = .004) (improvement in points), while there was no significant difference between groups for either the mHHS ( P = .487) or SF-36 ( P = .417) using the POPI technique. Conclusion: The MCID defined by an absolute value of improvement was unable to account for postoperative progress in a large proportion of higher functioning athletes. The POPI technique negated associated ceiling effects, was unrestricted by the baseline score, and may be more appropriate in quantifying clinically important improvement.

Background: Femoroacetabular impingement (FAI) is a common mechanical hip condition, prevalent in both the athletic and the general population. Surgical intervention is an effective treatment option that improves both symptoms and function in short- to medium-term follow-up. Few studies within the literature have reported the longer-term success of arthroscopic surgery. Purpose: The aim of this study was to quantify the 10-year survivorship and clinical outcome for patients treated arthroscopically for symptomatic FAI. Study Design: Case series; Level of evidence, 4. Methods: Patients from our hip registry (n = 119) completed patient-reported outcome measures (PROMs) including the modified Harris Hip Score (mHHS), University of California Los Angeles (UCLA) activity scale, 36-Item Short Form Health Survey (SF-36), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at a minimum of 10 years after arthroscopy (range, 10-12 years). Results were compared with baseline scores using the Wilcoxon signed rank test. The associations among several prognostic factors, which included age, sex, Tönnis grade, and labral treatment, and subsequent conversion to total hip replacement (THR) or repeat hip arthroscopy (RHA) were analyzed using the chi-square analysis. Relationships between range of motion and radiological findings with clinical outcome were also examined using Pearson correlation analysis. Minimal clinically important difference (MCID) was calculated using a distribution method (0.5 standard deviation of the change score), and substantial clinical benefit (SCB) was determined using an anchor method. Finally, receiver operating characteristic curves with subsequent Youden index were used to determine cutoffs for PROMs, which equated to a Patient Acceptable Symptom State (PASS). Results: A total of 8.4% of cases required conversion to THR, and 5.9% required RHA. Statistically significant improvements in mHHS, SF-36, and WOMAC scores, with high satisfaction (90%), were observed 10 years after surgery. No significant change was seen in activity level (UCLA score) despite patients being 10 years older. A high percentage of patients achieved MCID for mHHS (88%), SF-36 (84%), and WOMAC (60%). The majority of patients also achieved PASS (62% for mHHS, 85% for UCLA, 78% for SF-36, and 84% for WOMAC) and SCB (74% for mHHS, 58% for UCLA, 52% for SF-36, and 56% for WOMAC). Conclusion: Arthroscopic intervention is a safe and viable treatment option for patients with symptomatic FAI, and patients can expect long-term improvements and high satisfaction. Results indicated a high satisfaction (90%) and survivorship rate (91.6%), with excellent clinical outcome, 10 years after the initial procedure.

Objective: Femoroacetabular impingement (FAI) is a commonly recognized condition in athletes characterized by activity-related hip pain and stiffness, which if left untreated can progress to hip osteoarthritis. The aim of the study was to determine the effect of symptomatic FAI on performance in young athletes based on the hypothesis that athletes with FAI would show deficits in performance compared with healthy controls. Design: The functional performance of a cohort of preoperative, competitive sportsmen with symptomatic FAI (FAI group, n = 54), was compared with that of a group of age, sex and activity-level matched controls (n = 66). Outcome Measures: Participants performed functional tests including a 10-m sprint, a modified agility T-test, a maximal deep squat test and a single-leg drop jump (reactive strength index). Hip range of motion was assessed by measuring maximal hip flexion, abduction, and internal rotation (at 90 degree hip flexion). Results: The FAI group was significantly slower during the 10-m sprint (3%, P = 0.002) and agility T-test (8%, P < 0.001); flexion, abduction, and internal rotation values for the FAI group were reduced compared with controls (P < 0.001). No significant differences between groups were identified for squat depth or reactive strength index. The FAI group also reported higher levels of anterior groin pain during the 10-m sprint, modified agility T-test, and while squatting. Conclusions: Many sportsmen with confirmed FAI continue sports participation up to and after diagnosis, despite issues with activity-related pain and stiffness. This study highlights the functional limitations in speed, agility, and flexibility that are likely to be present in this group of FAI patients.

Background: A growing body of literature supports surgical intervention for femoroacetabular impingement (FAI) in young, active athletes. However, factors likely to influence results in this cohort are less clearly defined. Purpose: To quantify changes in validated patient-reported outcome measures (PROMs) and determine whether differences in baseline athlete demographic characteristics, intraoperative findings, and surgical techniques are associated with achieving improved outcomes and minimal clinically important difference (MCID) after arthroscopic management of sports-related FAI. Study Design: Case series; Level of evidence, 4. Methods: Data were prospectively collected from competitive athletes who underwent hip arthroscopy between January 2009 and February 2017. Athletes who underwent primary arthroscopic correction of sports-related FAI with labral repair were included providing they had a Tönnis grade ≤1 and a lateral center-edge angle ≥20°, excluding significant articular cartilage injury and lateral rim dysplasia. The modified Harris Hip Score, Western Ontario and McMaster Universities Osteoarthritis Index, University of California Los Angeles activity scale, and 36-Item Short Form Health Survey were used to measure outcomes at the 2-year follow-up. MCID was measured using 3 methods: a mean change method, a distribution-based method, and the percentage of possible improvement (POPI) method. Multivariate regression models were used to assess a number of diagnostic and surgical variables associated with good outcome and achieving MCID at follow-up. Results: At 2-year follow-up, statistically significant improvements were observed for all PROMs ( P < .001 for all), and 84% of athletes continued to play sport. Higher preoperative PROM scores reduced the likelihood of achieving MCID; however, returning to play was the strongest predictor of reaching MCID in this athletic cohort. Using absolute score change (mean change or distribution method) to calculate MCID was less accurate owing to ceiling effects and dependence on preoperative PROM scores. Conclusion: Athletes undergoing arthroscopy for sports-related FAI can expect a successful outcome and continued sports participation at 2 years postoperatively. The majority of athletes will achieve MCID. The POPI method of MCID calculation was more applicable to higher functioning athletic cohorts. Reduced preoperative PROM scores and the ability to return to sport increased the likelihood of achieving MCID in this population.

Purpose To measure the changes in athletic performance in athletes treated arthroscopically for femoroacetabular impingement and compare results to a matched controlled athletic cohort, over a 1‐year period. Methods Male athletes scheduled for arthroscopic correction of symptomatic FAI were recruited and tested (pre‐operatively and 1‐year postsurgery) for measures of athletic performance which included acceleration (10‐m sprint), change of direction speed (CODS), squatting depth, and reactive strength index (RSI). The FAI group was compared to a matched, healthy, control group who were tested at baseline and 1 year later with no disruption to their regular training or competition status; the prevalence of anterior groin pain during testing in either group was recorded. Hip range of motion (ROM) was also measured for both groups at baseline and at 1 year in the FAI group to look for change following intervention. Results Prior to surgery, the FAI group were slower than the control group (p < 0.001) for acceleration (3% slower) and CODS (10% slower). At 1 year, 91% of the FAI group returned to full competition at an average time of 17 weeks, while substantial reductions in pain were also noted during acceleration (51–6%, p = 0.004), CODS (62–8%, p = 0.001), and squat test (38–8%, p = 0.003). Significant improvements were seen in the FAI group for CODS (7%, p < 0.001) and squat depth measures (6%, p = 0.004) from baseline to 1 year (significant time × group interaction effects were noted for these also). The changes in performance in the control group over time were non‐significant across all of the measures (n.s.). At 1‐year postsurgery, there were no statistically significant differences between the groups for any of the athletic measures. There was a significant and clinically important improvement in range of hip motion in the FAI group at 1‐year postsurgery (p < 0.05). Conclusion Symptomatic FAI causes substantial reductions in athletic performance compared to healthy competitors placing these athletes at a distinct performance disadvantage. The results from the current study demonstrate that arthroscopic correction (including labral repair) in athletes with symptomatic FAI, reduces pain and restores athletic performance to a level which is comparable to healthy athletes, at 1 year. Level of evidence II.